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Graham AS, Ben-Azu B, Tremblay MÈ, Torre P, Senekal M, Laughton B, van der Kouwe A, Jankiewicz M, Kaba M, Holmes MJ. A review of the auditory-gut-brain axis. Front Neurosci 2023; 17:1183694. [PMID: 37600010 PMCID: PMC10435389 DOI: 10.3389/fnins.2023.1183694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023] Open
Abstract
Hearing loss places a substantial burden on medical resources across the world and impacts quality of life for those affected. Further, it can occur peripherally and/or centrally. With many possible causes of hearing loss, there is scope for investigating the underlying mechanisms involved. Various signaling pathways connecting gut microbes and the brain (the gut-brain axis) have been identified and well established in a variety of diseases and disorders. However, the role of these pathways in providing links to other parts of the body has not been explored in much depth. Therefore, the aim of this review is to explore potential underlying mechanisms that connect the auditory system to the gut-brain axis. Using select keywords in PubMed, and additional hand-searching in google scholar, relevant studies were identified. In this review we summarize the key players in the auditory-gut-brain axis under four subheadings: anatomical, extracellular, immune and dietary. Firstly, we identify important anatomical structures in the auditory-gut-brain axis, particularly highlighting a direct connection provided by the vagus nerve. Leading on from this we discuss several extracellular signaling pathways which might connect the ear, gut and brain. A link is established between inflammatory responses in the ear and gut microbiome-altering interventions, highlighting a contribution of the immune system. Finally, we discuss the contribution of diet to the auditory-gut-brain axis. Based on the reviewed literature, we propose numerous possible key players connecting the auditory system to the gut-brain axis. In the future, a more thorough investigation of these key players in animal models and human research may provide insight and assist in developing effective interventions for treating hearing loss.
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Affiliation(s)
- Amy S. Graham
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
| | - Benneth Ben-Azu
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Quebec City, QC, Canada
- Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
- Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada
- Institute for Aging and Lifelong Health, University of Victoria, Victoria, BC, Canada
| | - Peter Torre
- School of Speech, Language, and Hearing Sciences, San Diego State University, San Diego, CA, United States
| | - Marjanne Senekal
- Department of Human Biology, Division of Physiological Sciences, University of Cape Town, Cape Town, South Africa
| | - Barbara Laughton
- Family Clinical Research Unit, Department of Pediatrics and Child Health, Stellenbosch University, Cape Town, South Africa
| | - Andre van der Kouwe
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States
- Department of Radiology, Harvard Medical School, Boston, MA, United States
| | - Marcin Jankiewicz
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
| | - Mamadou Kaba
- Department of Pathology, Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa
| | - Martha J. Holmes
- Imaging Sciences, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Department of Human Biology, Division of Biomedical Engineering, University of Cape Town, Cape Town, South Africa
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- ImageTech, Simon Fraser University, Surrey, BC, Canada
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Kim DH, Seo YJ. Combination Therapy of Choline Alfoscerate With Ginkgo biloba Monotherapy in Age-Related Hearing Loss: Effects and Outcomes. J Audiol Otol 2023; 28:59-66. [PMID: 38052524 DOI: 10.7874/jao.2023.00192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/20/2023] [Indexed: 12/07/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Ginkgo biloba and choline alfoscerate are used as adjuvant treatment for presbycusis, but studies on how the monotherapy differs from the combination therapy are lacking. Therefore, this study aimed to compare the audiologic outcomes between Ginkgo biloba monotherapy and Ginkgo biloba and choline alfoscerate combination therapy. Subjects and. METHODS The study groups are divided into three: negative control, monotherapy, and combination therapy groups. All groups' pure tone audiometry was measured by dividing the study period into Initial, 3-6, 6-9, 9-12, 12-15 months, and checked whether differences between groups were present. RESULTS The combination therapy showed less gradient gap than the monotherapy, indicating less hearing loss rate than the monotherapy. Based on the Kaplan-Meier curve, the combination therapy showed better results in terms of survival time of hearing. CONCLUSIONS As a pharmacological treatment for presbycusis, combination therapy shows better results than monotherapy.
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Affiliation(s)
- Dae Hyun Kim
- Department of Otolaryngology, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Young Joon Seo
- Department of Otolaryngology, Yonsei University Wonju College of Medicine, Wonju, Korea
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Kansakar U, Trimarco V, Mone P, Varzideh F, Lombardi A, Santulli G. Choline supplements: An update. Front Endocrinol (Lausanne) 2023; 14:1148166. [PMID: 36950691 PMCID: PMC10025538 DOI: 10.3389/fendo.2023.1148166] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 02/07/2023] [Indexed: 03/08/2023] Open
Abstract
In this comprehensive review, we examine the main preclinical and clinical investigations assessing the effects of different forms of choline supplementation currently available, including choline alfoscerate (C8H20NO6P), also known as alpha-glycerophosphocholine (α-GPC, or GPC), choline bitartrate, lecithin, and citicoline, which are cholinergic compounds and precursors of acetylcholine. Extensively used as food supplements, they have been shown to represent an effective strategy for boosting memory and enhancing cognitive function.
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Affiliation(s)
- Urna Kansakar
- Department of Medicine, Division of Cardiology, Einstein Institute for Aging Research, Montefiore Health System, New York, NY, United States
| | | | - Pasquale Mone
- Department of Medicine, Division of Cardiology, Einstein Institute for Aging Research, Montefiore Health System, New York, NY, United States
- ASL Avellino, Montefiore Health System, New York, NY, United States
| | - Fahimeh Varzideh
- Department of Medicine, Division of Cardiology, Einstein Institute for Aging Research, Montefiore Health System, New York, NY, United States
| | - Angela Lombardi
- Department of Microbiology and Immunology, Montefiore Health System, New York, NY, United States
- *Correspondence: Angela Lombardi,
| | - Gaetano Santulli
- Department of Medicine, Division of Cardiology, Einstein Institute for Aging Research, Montefiore Health System, New York, NY, United States
- University of Naples “Federico II”, Naples, Italy
- Department of Molecular Pharmacology, Einstein-Sinai Diabetes Research Center (ES-DRC), Montefiore Health System, New York, NY, United States
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Kang M, Lee DB, Kwon S, Lee E, Kim WJ. Effectiveness of Nootropics in Combination with Cholinesterase Inhibitors on Cognitive Function in Mild-to-Moderate Dementia: A Study Using Real-World Data. J Clin Med 2022; 11:jcm11164661. [PMID: 36012898 PMCID: PMC9409895 DOI: 10.3390/jcm11164661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/03/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022] Open
Abstract
The clinical benefits of nootropics in the treatment of cognitive decline has been either limited or controversial. This study aimed to observe the effectiveness of cholinesterase inhibitor (ChEI) and nootropics combination in the treatment of cognitive impairment in dementia. Data were based on electronic medical records in a university health system. Patients with mild-to-moderate dementia and no history of prior cognitive enhancer use were included (n = 583). The subjects were categorized into the ChEI only group and the ChEI and nootropics combination group. The primary outcome measure was the change in cognitive function, as assessed by the mini-mental state examination (MMSE) from baseline to 300–400 days after the first ChEI prescription. Subsequent analyses were conducted in consideration of the dementia type, medical adherence, and type of nootropics. The changes in MMSE scores from baseline to endpoint were not significantly different between the two groups. In Alzheimer’s dementia, the combination group showed significantly less deterioration in MMSE language subscale scores compared to the ChEI only group (F = 6.86, p = 0.009), and the difference was consistent in the highly adherent subjects (F = 10.16, p = 0.002). The choline alfoscerate and the ginkgo biloba extract subgroups in Alzheimer’s dementia showed more significant improvements in the MMSE language subscale scores compared to the other nootropics subgroup (F = 7.04, p = 0.001). The present study showed that the effectiveness of ChEI and nootropics combination on cognition may appear differently according to the dementia type. This emphasizes the need for well-controlled studies to generalize the effectiveness of nootropics across various clinical settings.
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Affiliation(s)
- Minjae Kang
- Department of Psychiatry, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Dan Bee Lee
- Medical Information Team, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin 16995, Korea
| | - Sungchan Kwon
- Division of Gastroenterology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Eun Lee
- Department of Psychiatry, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea
- Institute of Behavioral Sciences in Medicine, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Woo Jung Kim
- Medical Information Team, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin 16995, Korea
- Department of Psychiatry, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin 16995, Korea
- Correspondence:
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